NCERT Solutions for Class 11 Chemistry Structure of Atom Part 1

NCERT Solutions for Class 11 Chemistry Structure of Atom Part 1 Class 11 Chemistry book solutions are available in PDF format for free download. These ncert book chapter wise questions and answers are very helpful for CBSE board exam. CBSE recommends NCERT books and most of the questions in CBSE exam are asked from NCERT text books. Class 11 Chemistry chapter wise NCERT solution for Class 11 Chemistry Some Basic Concepts of Chemistry Part 1 and all the chapters can be downloaded from our website and myCBSEguide mobile app for free.

NCERT Solutions for Class 11 Chemistry Structure of Atom Part 1

1. (i) Calculate the number of electrons which will together weight one gram.

(ii) Calculate the mass and charge of one mole of electrons.

2. (i) Calculate the total number of electrons present in one mole of methane.

(ii) Find (a) the total number and (b) the total mass of neutrons in 7 mg of

(Assume that mass of a neutron ).

(iii) Find (a) the total number and (b) the total mass of protons in 34 mg of at STP.

Will the answer change if the temperature and pressure are changed?

3. How many neutrons and protons are there in the following nuclei?

, , , ,

4. Write the complete symbol for the atom with the given atomic number (Z) andAtomic mass (A)

(i) Z = 17, A = 35

(ii) Z = 92, A = 233

(iii) Z = 4, A = 9

Ans. (i)

(ii)

(iii)

5. Yellow light emitted from a sodium lamp has a wavelength ( ) of 580 nm. Calculate the frequency () and wave number ( ) of the yellow light.

6. Find energy of each of the photons which

(i) correspond to light of frequency Hz.

(ii) have wavelength of 0.50 .

7. Calculate the wavelength, frequency and wave number of a light wave whose period is .

8. What is the number of photons of light with a wavelength of 4000 pm that provide 1 J of energy?

9. A photon of wavelength strikes on metal surface, the work function of the metal being 2.13 eV. Calculate (i) the energy of the photon (eV), (ii) the kinetic energy of the emission, and (iii) the velocity of the photoelectron (1 eV= ).

10. Electromagnetic radiation of wavelength 242 nm is just sufficient to ionise the sodium atom. Calculate the ionisation energy of sodium in kJ mol-1.

11. A 25 watt bulb emits monochromatic yellow light of wavelength of 0.57 m. Calculate the rate of emission of quanta per second.

12. Electrons are emitted with zero velocity from a metal surface when it is exposed to radiation of wavelength 6800 . Calculate threshold frequency ( ) and work function ) of the metal.

13. What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n =2?

14. How much energy is required to ionise a H atom if the electron occupies n = 5 orbit? Compare your answer with the ionization enthalpy of H atom (energy required to remove the electron from n =1 orbit).

15. What is the maximum number of emission lines when the excited electron of an H atom in n = 6 drops to the ground state?

16. (i) The energy associated with the first orbit in the hydrogen atom is atom-1. What is the energy associated with the fifth orbit?